The Perky-Pet Squirrel Shield Tube Feeder features specially designed patented Caged Ports engineered to allow birds to feed easily while making it almost impossible for squirrels to feed. The circular guards around the ports are also designed to prevent seed scattering, from either wind or squirrel interference. The metal feeder has a 1 lb. seed capacity and a removable base to allow for easy cleaning. Remember to clean your wild bird feeders every two weeks with a mild soap and water solution.